Metastatic sigmoid adenocarcinoma to the larynx: A case report and updated literature review

Abstract Metastatic laryngeal cancer is a rare entity, usually indicating an advanced disease once discovered. In this report, we are describing a case of a 60‐year‐old male patient with stage IV colorectal cancer (CRC), who presented to our clinic with dysphonia; further workups showed metastatic CRC.


| INTRODUCTION
Colorectal cancer (CRC) is the world's third most common cancer. 1 The incidence of CRC varies between high-and low-income countries. This variance is due to lifestyle differences and screening programs for premalignant lesions. The presentation of colorectal cancer varies depending on the involved location across the colon. More than 50% of patients die from CRC. Metastasis is usually present in 20% of patients at the time of diagnosis. [2][3][4][5][6] Local extension of hypo-pharyngeal and thyroid tumors to the larynx is common. Metastatic laryngeal involvement remains uncommon, accounting for less than 1 percent of all laryngeal malignancies. In 1988, Fertile et al. reported that skin melanoma and renal cell carcinoma as the most common primary cancers to metastasize to the larynx. Since 1988, 13 laryngeal metastases from colorectal cancer have been reported. Other cases are metastasis from the lung, bone, breast, thyroid, liver, and female genital tract. 3,5 Dysphonia is a term used to describe any impairment or change in the voice. It is caused by irregular vocal muscle oscillation, underlying muscle tension or dysfunction, incomplete closure of the glottis during vocalization, and pressure effect excreted on the vocal folds by a mass or tumor. 4

| CASE PRESENTATION
A 60-year-old Caucasian male patient, known case of Diabetes Mellitus (DM) type II and obstructive sleep apnea, on oral hypoglycemic agents and continuous positive airway pressure (CPAP), respectively, with no previous surgical interventions, was diagnosed with moderately differentiated sigmoid adenocarcinoma Stage IV (with distant metastasis to liver and lung at the time of presentation). The patient was treated with definitive chemotherapy by (FOLFOX/ Panitumumab regimen and he completed 12 cycles followed by maintenance therapy with 5FU/Panitumumab).
Subsequently, 18 months after the primary cancer diagnosis, the patient developed dysphonia for 2 weeks, without compressive respiratory symptoms or swallowing difficulties, and thus was referred to the ENT outpatient clinic. Physical examination of the oral cavity, throat, nose, and ears was unremarkable. Examination of the neck revealed no palpable lymphadenopathy. Fiber-optic examination revealed a paralyzed right vocal cord with a left vocal cord compensation; no masses or lesions were noted along the upper aerodigestive tract. The computerized tomography (CT) scan with contrast of the neck, thorax, and abdomen is displayed in Figure 1, which confirms the presence of the previously recognized distant lung and liver metastasis.

| RADIOLOGY
A contrast-enhanced neck CT scan (A) demonstrates a destructive right laryngeal mass that is destroying the cartilage and causing luminal narrowing with extra laryngeal extension (Figure 1), Chest and abdomen CT (B, C) with intravenous contrast demonstrates multiple lung nodules of varying sizes (red arrows), along with multiple liver lesions largest measuring (yellow circle).

| PATHOLOGY
Open surgical biopsy (transcervical approach) was obtained from the right cricoid cartilage and histopathology ( ENT via an awake tracheostomy. Later, the patient was sent to continue his treatment in palliative care; however, unfortunately, he was meet with his demise 8 months after the laryngeal metastasis diagnosis.

| DISCUSSION
In metastatic laryngeal involvement, transglottic involvement was the most common cause, compromising more than 40% of the reported cases, followed by supraglottic and subglottic in around 30% each and in less than 10% of the cases the true vocal cords were involved. Approximately, 70% of the cases were reported in men, with 59 years being the median age of diagnosis. The initial presentation in more than 60% was dysphonia, and the median time to laryngeal metastasis diagnosis was 3 years. 3 The treatment modalities for secondary laryngeal metastasis vary depending on the stage of the disease, the number of metastatic focus, and the involvement of other organs. In 2008, a case reported by Therasma et al., in which the laryngeal metastasis was managed with organ preservation surgery as the patient was in remission. 7 Another case by Marioni et al. was managed with total laryngectomy due to extensive laryngeal involvement but local control was achieved first at the time of laryngeal diagnosis. 8 Puxeddu et al., Sano et al., and Ta et al. managed their patients with a tracheostomy to protect the airway from local disease advancement. [9][10][11] In other cases reported, the local control of the disease was achieved by laser excision by Nd-YAG laser and CO 2 laser. 5,12 A summary of laryngeal metastasis secondary to colorectal cancer is shown in Table 1.
Due to unfamiliarity with secondary laryngeal cancers, there is no consensus on the treatment guidelines; treatment options depend on the stage at the time of diagnosis, solitary laryngeal involvement, or the presence of other metastatic focus. However, it is thought that laryngeal cancer is still underreported, as one postmortem study reported by Prescher et al. showed laryngeal involvement in six autopsies out of six patients with prostate cancer. Similarly, Horny and Kaiserling found 10 of 14 patients with hematopoietic malignancy found to have laryngeal metastasis. 13,14 Incidental laryngeal metastasis without symptoms is also evident, as reported by Xia et al. when a PET/CT (Positron Emission Tomography/Computed Topography) was performed for an elevated AFP (Alfa Fetoprotein) which showed increased uptake in the larynx. 15

| CONCLUSION
Any laryngeal lesion in patients with malignancy or high-risk factors for malignancy should be worked out promptly to avoid any delay in diagnosis and management. Although, secondary laryngeal malignancy is rare, micrometastasis and subclinical disease are evident; however, laryngeal cancer metastasis indicates advanced disease and poor prognosis, and the interventions aim to avoid any respiratory distress or direct mortality related to airway obstruction.

AUTHOR CONTRIBUTIONS
Adham A. Aljariri, Abdulqadir J. Nashwan, Rani Hammoud, Bara Wazwaz, Sameer Alhyassat, and Hasan A. Haider were involved in data collection, literature search, and manuscript preparation. All authors read and approved the final manuscript.